An explosion was prevented when a gas bottle was swiftly moved away from a fire at the War and Peace Revival.
The flames on a picnic table broke out at the show at Folkestone Racecourse at 2.30am today.
On-site firefighters put out the flames but also removed a nearby small three-litre camping cylinder just as heat began to reach it.
Folkestone Fire Station watch manager James Kirk said: “The gas container was a small camping bottle, which was pulled away in time.
“The fire destroyed the picnic table but did not spread further.
“It was a small fire and by the time we got there it had already all been put out by the on-site firefighters.
“It was particularly windy that night so we think that a gust caused flames to spread from a campfire nearby.”
The military show has its own private firefighting force to guard material vulnerable to blazes such as tents.
But Kent Fire and Rescue Service is also called out if there is an incident.
The drama happened after the first day of the military show, which continues until Sunday and is expected to attract as many as 100,000 people.